The subject matter of the present invention relates to a swivel disposed in a perforating gun for enabling opposite parts of the perforating gun to independently swivel about an axis.
Perforating guns are sometimes disposed in deviated boreholes. When disposed in the deviated borehole, the perforating gun is rotated in order to direct the charges in a selected direction into the formation. Normally, a swivel located in the tubing string above the firing head of the perforating gun enables the perforating gun to rotate. However, since the swivel is located in the tubing string above the firing head of the gun, certain problems are created: (1) alignment error builds up in oriented guns, (2) torque builds up along the gun string, and (3) the swivel interferes with certain components above the gun string, such as hydraulic flow tubes, drop bars and slickline tools.